1. Field of the Disclosure
The disclosure relates generally to plugs and other devices that utilize composite threaded members subjected to loads during downhole applications.
2. Background Art
Devices such as frac plugs and bridge plugs are commonly utilized in wellbores to perform a variety of downhole operations. Some such plugs include a composite threaded member, such as a composite threaded mandrel, on which another member or device, such as a guide is threaded, to protect the plug during run-in of the plug in the wellbore and from other subsequent downhole conditions or operations. The composite material often is a fiber-based material, such as fiber glass. Often, the shear values of such composite mandrels in some applications are insufficient to provide pitch and wind angles for the threads able to withstand high loads applied on such members during run-in and later wellbore operations. A guide is typically made from a phenolic material with internal threads that mate with the threads on the composite mandrel. In some downhole applications, such threading arrangement is not sufficient to protect the composite member. Therefore, there is a need to provide downhole devices, such as plugs, that include threaded composite members that can withstand higher loads than contained in currently available devices, including, but not limited to, frac plugs and bridge plugs.
The disclosure herein provides downhole devices that include a threaded member placed around a recess on a composite member possessing greater strength than the strength of the composite member, so that the combination of the composite member and the threaded member can absorb greater loads than loads the composite member can absorb during downhole operations at present.